1. Technical Field
The present invention relates to a linear encoder.
2. Background Information
An example of a linear encoder is described in German Patent Disclosure DE 197 46 532 A1. This linear encoder serves to measure lengths as well as travel distances and the linear encoder is used particularly in machining tools for measuring the relative motion of a tool with respect to a workpiece to be machined. The linear encoder can be used in coordinate measuring machines and increasingly in the semiconductor industry as well.
This known linear encoder includes a housing which protects the scale against environmental factors. For that purpose, the housing has an elongated tubular profile section whose face ends are each closed off with a cap. A resilient sheet-metal tongue is screwed onto at least one of these caps. The tongue contacts the scale resiliently and thus establishes an electrical connection between the measuring graduation of the scale and the cap.
This sheet-metal tongue is a problematic part, which is relatively complicated to produce and assemble.